A new MMC control strategy based on One-Cycle-Control and capacitor voltage balance

Abstract

Modular Multilevel Converter (MMC) is a new converter system applied in medium- and high-voltage situation, which can be extended without limit. But with extension, the control and the structure become complex, making the cost and engineering effect not ideal. In order to simplify, this paper introduce One Cycle Control (OCC) into MMC based on the principles of carrier disposition PWM. With less hardware dependence, the Virtual Loop Mapping is used to balance the capacitor voltage, which makes further efforts to simplify the structure. The simulation and experiment validate the effectiveness of the proposed method.